Thanks!
All the installation criteria you state appears to be met (ducts exiting basement wall at extremes of joist spacing, height, etc.).
Both pipes terminated with 45-degree elbows, each turned outward from the other at a 45-degree angle to the ground.
Woke up with house temperature at 67 degrees; checked the L.E.D.s and found two-blinks, indicating the pressure swsitch open. I'm about to go out and clear any buildup of snow away from the area, just in case...
Any other ideas?
Thanks again.
Randy
No major buildup, just about 2-3" of hard-hard snow (might as well call it ice) on the mulch. Without accurate measuring, I'd say the pipes are 14" above the finished grade (top of shallow layer of__frozen__mulch).
As a temporary measure, I've left the combustion air alternate side entrance cap off the unit (the pipes are connected running straight up). I realize this will draw air from the house, but at 2600 sqft (not counting unfinished basement). The exhaust is still ducted to the outside.
I won't rule out that a small animal has gotten in, but it could only have been a bird, based on the distance to the ground.
What about a bit of electric heat-trace around the combustion air inlet? Given our similar locations, you know what the temperature here (in Toledo) is like last night/today.